Detection of an extremely large impact flash on Jupiter by high-cadence multiwavelength observations

TL;DR

This paper reports the first high-cadence, multiwavelength observation of a massive impact flash on Jupiter, revealing its energy, frequency, and spectral characteristics, with implications for impact rates on the planet.

Contribution

First detection of a large impact flash on Jupiter using multi-band observations, providing detailed energy and spectral data, and estimating impact frequency.

Findings

Impact energy approximately two megatons of TNT.

Impact frequency roughly once per year.

Impact flash exhibited a blackbody temperature of about 8300 K.

Abstract

We report the detection of an optical impact flash on Jupiter on 15 October 2021 by a dedicated telescope, Planetary ObservatioN Camera for Optical Transient Surveys (PONCOTS), for the first time. Our temporally resolved three-band observations of the flash allowed investigations of its optical energy without the need for approximations on the impact brightness temperature. The kinetic energy of the impactor was equivalent to approximately two megatons of TNT, an order of magnitude greater than that of previously detected flashes on Jupiter and comparable with the Tunguska impact on Earth in 1908. This detection indicates that Tunguska-like impact events on Jupiter occur approximately once per year, two-three orders of magnitude more frequent than terrestrial impacts. The observed flash displayed a single-temperature blackbody spectrum with an effective temperature of approximately 8300 K without clear temporal variation, possibly representing common radiative features of terrestrial Tunguska-class superbolides.